Adjustable mill screen



m. L/ WM March 1, 1932. L7 D. PETERS 1,847,193

ADJUSTABLE MILL SCREEN Filed Oct. 18, 1930 2Sheets-Sheei l V 1 g/ EE=2EE2' \5 34mm 44 to:

' l2 fliers March 1, 1932. D. PETERS 1,847,193

ADJUSTABLE MILL SCREEN Filed Oct. 18, 1930 2 Sheets-Sheet 2 Patented Mar. 1, 1932 PATENT OFFICE LOUIS D. PETERS, OF JACKSON, OHIO ADJUSTABLE MILL SCREEN Application filed October 18, 1930. Serial No. 489,665.

It has been customary in hammer and pulverizing mills, to insert screens having perforations of different size, according to the materials to be acted upon and the degree I of fineness to which they are to be reduced before passage through the screen. Removal of one screen and substitution of another, entails quite an amount of time and during the interchange of screens, the mill is of course inactive so that loss of production follows. To overcome this difficulty, it has been roposed to provide such mills with adjusta le screens consisting of relatively fixed and slidable sections, relative adjustment of said sections serving to vary the elfective size of the perforations through which the material must pass. With the adjustable screen mills, however, rather complicated provision has been proposed for adjusting the slidable screen sections, and moreover, difficulty and loss of time have been entailed whenever it has been necessary to remove a worn or damaged screen and substitute a new one.

My invention aims to provide a new and improved construction whereby the slidable screen section may be quickly and easily adjusted by means of one screw, and moreover, aims to provide a construction wh1c h permits quick and easy removal of the entire screen from the machine whenever desired. Then too, it is a further aim to provide simple, easll constructed and inexpensive means for slida ly connecting the two screen sections with each other, said means embodying guides upon which the upper section of the mill casing normally rests so as to hold the screen against longitudinal movement wlthln grooves in which its edges are recelved.

With the foregoin in view, the invention resides in the novel suij ect matter hereinafter described and claimed, description being accomplished by reference to the accompanying drawings.

Fig. 1 is a vertical transverse sectional view through a mill embodying my improvements, this view being cut substantially on line 1-1 of Fig. 2.

. Fig. 2 is a vertical longitudinal sectional view on line 2-2 of Fig. 1. n Fig. 3 is a perspective view of a portion of the lower section of the mill casing, showing parts of the adjustable screen and its adjusting means.

Fig. 4: is a perspective view showing the two sections of the screen in juxtaposition.

In the drawings above briefly described, a preferred construction has been illustrated and while such construction will be specifically explained, it is to be understood that within the scope of the invention as claimed, variations may be made.

As usual, the mill casing comprises upper and lower sections 5 and 6 respectively, the upper section being usually hinged at 7 to the lower section. The upper section 5 and the rotor 8, are of conventional construction and require no explanation. The structure of the lower section 6 however, is varied and will be described below.

Formed in the inner sides of the opposed side walls 9 of the lower casing section 6 are two arcuate grooves 10 which are directly opposed to each other and have their ends opening through the upper edges of said walls 9. These open ends of the grooves 10 are inwardly spaced from the end walls 11 of the casing section 6, and the inner sides of said ends 11 are preferably beveled as shown at 12. A relatively fixed screen section 13 of arcuate form, has its curved edge portions received in the opposed grooves 10, the ends of said screen section 13 being bent horizontally outward at 14, then bent downwardly at 15 and finally bent inwardly as at 16, the portions 14 and 15 being horizontal and the former being so positioned as to normally engage the lower end of the upper casing section 5, as seen in Fig. 2. A shiftable screen section 17 lies slidably against the outer side of thesection 13, and the ends 18 of said shiftable section 17 are bent horizontally outward and engaged with the guides constituted by the formations 14, 15 and 16'. Thus, screen section 17 is mounted for sliding transversely of the screen section 13, so that the erforations 19 of said section 17 may be ma e to register more or less with the perforations 20 of the section 13, thus varying the efi'ective size of the screen perforations as occasion may demand.

For shifting the screen section 17 as required, a single screw 21, havin a hand wheel 22, is provided. This screw 1s threaded through anut 23 having an attaching plate 24 which lies vertically against the outer side of one of the walls 9 and is secured thereto by means hereinafter described. The screw 21 passes through a relatively large opening 25 in the wall 9 and the inner end of said screw is rotatably received in a notch 26 formed in a lug 27 which projects downwardly from the screen section 17, said screw being provided with shoulders 28 and 29 abutting opposite sides of said lug, so that whenever the screw is moved inwardly or outwardly, the screen section 17 will be similarly moved. The opening 25 is of suflicient size to allow downward shiftin of the screw 21 from engagement with t e lug 25 whenever it is necessary to remove the entire screen from the machine, and after such disenga ement of screw and lug, the screen ma be sli longitudinally of the grooves 10 an hence easily removed to be replaced by another. To allow disengagement of the screw 21 from the lug 27, the attaching means for the nut 23 may be entirely removed, or if the structure herein disclosed be used, it is only necessary to release said attaching means.

In the form of construction herein illustrated, the plate 24 is provided with a vertically elgngated slot 30 and with a circular opening 1. Two fasteners 32 and 33 pass through the slot and opening respectively and are engaged with the ad'acent wall 9, so that normally the nut 23 is edly mounted and there is no possibility of the plate 24 shifting in any direction. Upon removal of the fastener 33 from the opening 31, and loosening of the fastener 32, the plate 24, nut 23 and screw 21, may bodily shift downwardly to disengage said screw from the lug 27. The screen may then be quickly and easily removed and a new one substituted, and b re-shifting the parts 23, 24 and 21, to their previously raised positions, the screw ma be easily engaged with the notched lug of the new screen. Tightening of the fastener 32 and re-insertionof the fastener 33 will now securely lock the screw and its carrying means in their normal positions.

It will be seen from the foregoing that simple and inexpensive, yet efiicient and reliable construction has been provided for carrying out the objects of the invention. Particular attention is invited to the fact that onl one adjusting screw is necessary for the shifizable screen section 17. Moreover, the provision which has been made for readily disconnecting this screw from the shiftable screen section, is of unusual merit. Then too attention is invited to the novel way of formin the guides for the flanges 18 of the shiftable screen section 17.

I claim 1. In a mill, a casing composed of a lower section having opposed vertical walls, and an upper section resting removably upon said lower section, said walls having opposed arcuate grooves whose ends open through the upper edge of said walls, a fixed arcuate screen section extending between said walls and having its curved edges received in said grooves, the ends of said fixed screen section abutting the lower edge of said upper casing section to hold said fixed screen section a ainst sliding along said grooves, a shifta le arcuate .screen section contacting with the outer side of said fixed screen section, means slidably connecting the two screen sections, and means for sliding said shiftable screen section with respect to said fixed screen section, the two screen sections being slidable bodily alon said grooves when permitted to so slide, t ereby allowing removal of said screen sections without disturbing the relation of said opposed walls.

2. In a mill, a casing section having oposed side walls, the inner sides of said walls eing provided with opposed arcuate grooves whose ends open through the upper edges of said walls, a relatively fixed arcuate screen section extending between said walls and having its curved edges received in said grooves, a shiftable arcuate screen section contacting with the outer side of and slidably connected with said relatively fixed section, a lug projecting downwardly from said shiftable screen section and having a downwardly opening notch, a horizontal adjusting screw whose inner end is received in said notch and provided with shoulders abuttin opposite sides of said lug, a nut throug which said screw is threaded, and releasable means securing said nut to one of said walls, the latter having an opening through which said screw passes, said opening being of sufficient size to allow movement of sald screw y from said notch upon release of said securing means, thereby allowing sliding of both y screen sections along said grooves.

3. In a mill having a wall provided with an opening, and a shiftable screen member at the inner side of said wall mounted for movement toward and from the latter; an adjusting screw passing through said opening and having spaced shoulders at its inner end, a lug on said screen member en aged with said shoulders and having a note receiving said screw, a nut through which said screw is threaded, and releasable means securing said nut to said wall, the aforesaid opcnin being of sufficient size to allow shifting 0 said screw from engagement with said notch upon release of said nut securing means.

4. a mill havingta wall provided with an g openmg, and a shi able screen member at the inner side of said wall mounted for movement toward and from the latter; an adjusting screw passing through said opening and having spaced shoulders at its inner end, a lug on said screen member engaged with said shoulders and having a notch receiving said screw, a nut throu h which said screw is threaded said nut aving a vertical ca mg plate, and two fasteners for securing said plate to said wall, said plate bein rovided with a slot receiving one of sai asteners and with an openin snugly receiving the other fastener, where y loosening of said one fastener and removal of said other fastener will allow sliding of said plate and nut to iafiect disengagement of said screw from said in testimony whereof I aflix my si ature.

LOUIS D. PE RS. 

